We queried Twitter about the research and the fake account, which
was still live even as we type this. Twitter declined comment on
this particular case but did confirm that it was against its
terms of service to buy followers, sell them or use a service
that automically adds them.

We also noticed that there's a Twitter user, Kevin Railsback, who
goes by @kevinrailsback on that service but has the username
"krails" on a lot of other websites. We asked him if, by chance,
@krails used to belong to him but got hijacked somewhere along
the way. We haven't heard back yet.

If the now clearly fake account did belong to the real Railsback,
that might explain its why it was impossible for Twitter to
detect.